LECT. IV.J THE ROOT. BULBS. 183 



when exhausted of the nutriment contained in 

 them, assume the appearance of lacework. In 

 this bulb, also, the young bulbs are formed within 

 the second layer of the present year's bulb *. 



* * With divided Layers. 



In this division of the concentric laminated 

 bulbs, the layers, as has been already stated, do 

 not form an entire sheath. In the garden Hyacinth 

 (Hyacinthus orient alls), which I select as an ex- 

 ample because it can be easily procured, they 

 comprehend two thirds only of the circumference 

 of the circle. Each layer is fleshy and thick in the 

 centre, and becomes gradually thinner towards 

 its edges until it terminates in a membranous 

 film, embracing the layers within it in the same 

 manner as the hand holds a ball which it cannot 

 completely enclose. The deficient portion of each 

 layer is always on the opposite side to that of the 

 layer immediately beneath it. The caudex has 

 the character of a segment of a hollow sphere, 

 on the convex surface of which the layers are 

 attached ; whilst a considerable number of fleshy 

 roots protrude from the circumference -j~. The 



* Fig. 3. a vertical section of the same bulb. a. the suc- 

 cessive succulent layers extended into the stem ; b. the ex- 

 hausted reticulated layers ; c. the caudex ; d. the young bulb. 



f Vide Plate 3. fig. 6 and 7. a. The body of the bulb ; b. 

 the manner in which the layers overlap each other ; c. the 

 radical plate, with the roots separated from one side of the cir- 



N4 



